Making printers&#39; overlays and underlays.



UNITED/STATES rArE roF ioE.

WILLIAM E. RADTKE, OFMILWAUKEE,Wisconsin,

MAKING rnrirrnns OVERLAYS AND UNDERLAYS.

No Drawing.

To all whom it may concern:

Be it known that I, lVILLIAM E. RADTKE, a citizen of the United States, and resident of Milwaukee, in the countyof Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Making Printers Overlays and Underlays; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention consists in the herein described method for the production of printers overlays and underlays from a product that of itself consists of a paper base coated upon one or both sides with a material that is soluble in water, my method being economical and wholly manual, thereby obviating the employment of acids and the skill of an etcher to obtain satisfactory results, said process being one that may be readily carried out by printers and pressmen.

My invention also extends to the product of said method, the same being utilized to emphasize gradations of tone in prints from what are known as half-tone and wash-print plates, as well as to protect the finer parts of such plates and thereby extend their usefulness.

The aforesaid material from which overlays and underlays are produced by my novel method is hereinafter referred to as overlay-board, and in carrying out said method to its fullest extent, an impression of a printing-plate is first made upon the tympan-sheet of a printing-press with a suitable ink applied to said plate. Afterward the plate is again inked and a strong impression of the same made upon one coated side of a sheet of overlay-board of the above description fed to the press, the coated reverse side of the sheet being inked under pressure by absorption from the previous impression upon said tympan-sheet. The overlay-board proof of the plate is nowcovered with a waterproof powder on both sides and the powder permitted to dry on the ink to which it is adhesive. The proof is then immersed for a time in a bath of hot water to rapidly soften the coating of the overlayboard not protected by the combined ink and powder upon same, after which said proof is removed to a smooth surface, preferably glass, and a moist sponge employed to wipe away the unprotected and softened coating from the paper base of the overlay-board, whereby the high lights of the aforesaid proof are removed, the shades and solids bebase of the overlay-board is easily removed a specification of Letters Patent. Patented July 28, 1914." Application filed November 1, 1912.. sriain 729,085. i

by the sponging operation, and the waterproof powder occurring on the vback impres- SlOI1,b611'lg lighter than upon the heavier front impression of the proof only the solids of'said back impression are left, after sponging, this being an advantageous result. The proof is now dried and preferably subjected to a bath of suitable oil to render it pliant, and translucent where the coating of the overlay-board has been removed, as well as to harden the combined ink and powder aforesaid that might otherwise become sticky under some conditions. After the oil bath, the product is placed between blotters or other suitable absorbent material under slight pressure to remove excess oil, whereupon said product is ready for' utilization as an overlay on a printing press tympan, or as an underlay of the plate from which the aforesaid impressions were had.

It is practical, and within the scope of my I invention, to employ overlay board devoid of soluble in water coating upon one side of its paper base, in which case no tympansheet impression of a printing-plate is necessary, the coated side only of a sheet of said overlay board being treated in the manner aforesaid to obtain an overlay or underlay for a job of printing in which greater excellenceof result is not requisite.

I claim:

1. The method of producing a printers overlay and underlay consisting in making an ink impression of a printing-plate upon a Y printing press tympan-sheet, then making a I similar impression of the same plate upon one side of a sheet of material consisting of a paper base having a soluble in water coating upon both sides thereof, ink of the previous impression being absorbed by the coating of the other side of said sheet; covering the impressions on both sides of the proof with a waterproof powder that combines with the ink of said proof, subjecting the product to awater bath, thereafter sponging away of said coating not protected by the combined ink and waterproof powder, and thendrying the product.

p 2. The method of producing a print-ers overlay and underlay consisting, in making an ink impression of a'printing-plate upon a printing-press tympan-sheet, then making a similar impression of the same plate upon one side of a sheet of material consisting of a paper base having a soluble in water coat ing upon both sides thereof,.inkof the previous impression being absorbed by the coating of the other side'of said sheet covening the impressions on both sides of the proof with, a waterproof powder that combines with the ink' of said proof; subjecting the product to a water bath, th'erea'fter-sponging' away of said coating not protected by the combined ink' and waterproof'powder, dry.- ing the product, thereafter subjecting the same to an oil bath, and finally removing eX- cess oil therefrom.

In testimony that I' claim the foregoing I have hereunto-set my: hand at Milwaukee, in the county of Milwaukee and State of VVisconsin in the presence of two witnesses.

W. E. RAD'IEKE;

Witnesses:

N. E. OLIIHANYD, M. DOWNEY.

flopi'esof this patent may be obtainedibrfwe cents each; by addressing the Commissioner of Patents Washington, Di 0.?" 

